The present invention is directed toward a safety device and more particularly toward a safety device which is intended to prevent a worker who is working in a high place such as a bridge or the like from falling.
Safety devices of the class to which the present invention pertains and which protect a worker from injury or death caused by falling are known. These prior art devices are personal fall arrest systems and are used in conjunction with other components such as an anchoring means for the device and a body harness.
These known devices are comprised of a housing which is adapted to be suspended from an elevated structure. A rope or cable winding drum is rotatably mounted in the housing and a spiral spring drives the drum in a direction which continuously tends to wind the cable around the drum. A centrifugally operated brake mechanism responds to an initial fast rotation of the drum in the unwinding direction and brakes the rotation of the drum to prevent further unwinding thereof.
In use, these known safety devices are fixed to a structure such as a building, bridge or the like and the cable extending therefrom is fastened to a worker's belt or harness. Under normal working conditions, i.e. as the worker moves from one place to another and the rope is drawn in and out of the housing at a reasonable speed, the centrifugal brake is never engaged since the speed of rotation of the drum is relatively slow. Accordingly, the drum rotates freely and the rope is drawn out or wound on the drum freely. In the event of a fall, however, the rope is drawn out rapidly and the drum is then rotated at a high speed. As a result, the centrifugally operated brake is actuated preventing further rotation of the drum which stops the rope from being drawn out. This prevents injury or death to the worker which otherwise would occur as a result of the fall.
Former safety devices such as that described above are extremely useful and do prevent serious injury and death to workers. However, they all suffer from a common deficiency. When a worker has fallen and is being suspended by the rope from the safety device, additional lifting equipment is needed to lift the worker back up to safety.
Because of the elevated locations at which workers using such safety devices are normally working, it is often difficult and time consuming to get the necessary lifting equipment into place. In some situations, it may be possible for a worker to climb to safety. However, it is not uncommon for a worker to be slightly injured during the accident thereby making it difficult for him to lift himself to safety. A similar problem exists if the worker has fallen into a confined space such as a sewer, tank or the like.